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PubMed2025

A Genomic Alteration in GATA3 Affects Treatment Responses With a CDK4/6 Inhibitor Collaborating With p18INK4C Expression in Advanced Breast Carcinoma.

Cyclin-dependent kinase 4 and 6 inhibitor (CDK4/6i) with endocrine therapy benefits patients with hormone receptor-positive, human epidermal growth receptor 2-negative breast carcinomas. However, most tumors develop resistance to CDK4/6i during the course of therapy. Although preclinical studies have proposed molecular mechanisms for the resistance, predictive markers are yet to be discovered. We investigated the tumor molecular profiling in 42 patients with advanced-stage breast carcinoma who received CDK4/6i therapy. The tumors carrying a GATA-binding protein 3 (GATA3) gene mutation, mainly a frameshift variant, showed a better treatment response compared with other tumors. Furthermore, we explored the potential underlying mechanism of this association. To that end, nuclear expression of p18, one of the INK family proteins, was found to be positively associated with the GATA3 mutation, as well as a CDK4/6i treatment response. Therefore, our study suggests that a GATA3 gene mutation, collaborating with p18 protein expression in tumor nuclei, may have a predictive value for CDK4/6i therapy in breast carcinoma.

Humans↗
PubMed2026

Impact of BRCA2 pathogenic variants on outcomes to first-line CDK4/6 inhibitors plus endocrine therapy in HR-positive/HER2-negative metastatic breast cancer.

BACKGROUND: Currently, three cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) are approved in combination with endocrine therapy (ET) as first-line treatment of patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC). The impact of homologous recombination repair (HRR) pathogenic variants (PV) on outcomes with first-line CDK4/6i plus ET in HR-positive/HER2-negative MBC remains uncertain. PATIENTS AND METHODS: We conducted a multicenter, real-world, case-control study including 233 patients with HR-positive/HER2-negative MBC treated with first-line CDK4/6i and ET. Among them, 116 presented HRR PVs and 117 were matched controls with negative germline testing. The primary objective was to compare progression-free survival (PFS) and overall survival among germline-BRCA2 PV carriers, other HRR PV carriers, and controls. To minimize baseline differences in prognostic factors between PV carriers and controls, inverse probability of treatment weighting was applied. Molecular analyses in pre-CDK4/6i samples among patients with BRCA2 PV were carried out, including RAD51-foci, PAM50 intrinsic subtype, and RB1 loss of heterozygosity (LOH). RESULTS: Among the included 233 patients, median age at diagnosis was 45 years (interquartile range 39-56) and 33% had de novo metastatic disease. Primary resistance to adjuvant ET was present in 10% and secondary resistance in 27%. After a median follow-up of 44 months, patients with germline-BRCA2 PVs (n = 67) had significantly shorter PFS [11 versus 27 months; adjusted hazard ratio (aHR) 2.73, 95% confidence interval (CI) 1.65-4.51, P < 0.001] compared with controls. Among patients with endocrine-sensitive disease, germline BRCA2 PV carriers had markedly shorter PFS (median PFS 12 versus 39 months; aHR 4.04; 95% CI 1.82-8.98, P < 0.001). Exploratory analyses revealed RB1 LOH before CDK4/6i-treatment in most evaluable BRCA2 tumors. CONCLUSIONS: BRCA2 PVs were independently associated with poorer outcomes to first-line CDK4/6i plus ET in HR-positive/HER2-negative MBC compared with controls, especially relevant among patients with endocrine-sensitive disease. These findings suggest that patients with a germline PV in BRCA2 may require alternative first-line strategies.

Humans↗
PubMed2026

Adjuvant CDK4/6 inhibitors in early-stage breast cancer: Clinical evidence and considerations for risk stratification and treatment selection.

Hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer is the most common biologic subtype and carries a persistent risk of recurrence, particularly in patients with high-risk, early-stage disease. Cyclin-dependent kinase 4 and 6 inhibitors, initially established as a standard component of first-line therapy in the metastatic setting based on improvements in progression-free and overall survival, have since been evaluated in the adjuvant setting. While adjuvant palbociclib did not improve invasive disease-free survival, the monarchE and NATALEE trials demonstrated that abemaciclib and ribociclib, respectively, reduce recurrence risk in patients with high-risk, early-stage disease, with emerging overall survival data further supporting their use. However, the absolute magnitude of benefit varies substantially with baseline risk, and treatment-related toxicity and adherence challenges must be considered, as approximately 20% to 25% of patients discontinue therapy before completion. The integration of these agents into clinical practice also intersects with ongoing efforts to deescalate axillary surgery, as treatment eligibility has been largely defined by anatomic staging, particularly nodal status. Available data suggest that the incremental impact of axillary surgery on identifying candidates for cyclin-dependent kinase 4 and 6 inhibition is modest, especially among the favorable-risk populations now eligible for surgical deescalation. As the field evolves, advances in molecular risk stratification, genomic profiling, and dynamic biomarkers are poised to shift treatment selection from anatomic staging toward biologically driven approaches. Multidisciplinary decision-making that integrates tumor biology, anticipated absolute benefit, toxicity, patient preferences, and surgical considerations will be essential to ensure individualized care.

Humans↗
PubMed2026

Cyclin-dependent kinase 4 and 6 inhibitors and the breast cancer immune ecosystem: immune remodeling, resistance, and therapeutic reprogramming.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6 inhibitors) combined with endocrine therapy have become a therapeutic backbone for hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer, yet durable disease control is frequently limited by intrinsic and acquired resistance. Canonical tumor-cell mechanisms, including retinoblastoma-pathway escape, cyclin E-cyclin-dependent kinase 2 (CDK2) activation, endocrine adaptation, and phosphoinositide 3-kinase (PI3K)-AKT-mechanistic target of rapamycin (mTOR) signaling, explain only part of this failure because they do not fully capture dynamic immune and stromal remodeling. Preclinical and translational studies indicate that early CDK4/6 inhibition can enhance antigen presentation, activate interferon-related programs, restrain regulatory T cells, and promote a T-cell-inflamed state. These effects are conditional and may not persist during prolonged treatment. Sustained therapy can instead drive heterogeneous resistant niches characterized by stromal remodeling, myeloid recruitment, checkpoint adaptation, and T-cell dysfunction. This immune-state dependence provides a rationale for immune checkpoint blockade, although clinical combinations have shown mixed efficacy and clinically relevant hepatic, pulmonary, and hematologic toxicities. Sequential or lead-in strategies therefore warrant prospective evaluation. Oxidative phosphorylation (OXPHOS) and redox adaptation may sustain selected resistant states and expose context-dependent ferroptotic vulnerabilities. Ferroptosis may connect tumor-cell killing with immune regulation, whereas nanomedicine may improve tumor-selective delivery. Both strategies remain largely preclinical and require further evaluation of pharmacokinetics, biodistribution, toxicity, manufacturability, and immune-cell safety. This Review distinguishes intrinsic from acquired resistance across interpatient, intratumoral, spatial, and temporal dimensions. It integrates tumor-cell escape with cytokine, immune, stromal, vascular, and metabolic remodeling and summarizes emerging therapeutic strategies. We further propose a candidate biomarker-informed framework that integrates genomic profiling, spatial immune architecture, circulating biomarkers, T-cell receptor (TCR) dynamics, transcriptomic and single-cell analyses, artificial intelligence (AI)-assisted multimodal integration, and longitudinal sampling. This framework is intended to support biomarker development and prospective trial design rather than current clinical decision-making, providing a translational basis for testing state-informed and sequence-aware therapeutic strategies.

Humans↗
PubMed2026

Corneal Epithelial Alterations Associated With Cyclin-Dependent Kinase 4/6 Inhibitor Therapy in Hormone Receptor-Positive Breast Cancer.

IMPORTANCE: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are standard therapy for hormone receptor-positive (HR+), HER2-negative breast cancer. By blocking the G1/S cell-cycle transition, these agents may impair renewal of the corneal epithelium. No controlled study has systematically evaluated corneal epithelial changes in patients receiving CDK4/6 inhibitors. OBJECTIVE: To determine whether CDK4/6 inhibitor-based therapy is associated with cornealepithelial alterations independent of aromatase inhibitor exposure and tear film dysfunction. DESIGN, SETTING, AND PARTICIPANTS: Retrospective comparative cross-sectional study at a tertiary ophthalmology center. A total of 132 women were enrolled: 45 receiving a CDK4/6 inhibitor plus an aromatase inhibitor (CDKAI group), 44 receiving aromatase inhibitor monotherapy (AI group), and 43 age-matched postmenopausal controls without systemic oncologic therapy. EXPOSURES: CDK4/6 inhibitor (ribociclib, palbociclib, or abemaciclib) combined with an aromatase inhibitor; aromatase inhibitor alone; or no systemic oncologic therapy. MAIN OUTCOMES AND MEASURES: Prevalence and severity of punctate epitheliopathy and vortex keratopathy, assessed by a masked ophthalmologist. Secondary outcomes included Schirmer I test, tear film break-up time, and Ocular Surface Disease Index (OSDI). RESULTS: PE was present in 44.4% of eyes in the CDKAI group vs 4.7% in the AI group and 2.3% in controls (&#x3c7;&#xb2; = 34.31; P < .001). All moderate (13.3%) and severe/complicated (8.9%) PE cases occurred exclusively in the CDKAI group. Vortex keratopathy was observed in 13.3% of CDKAI patients and in none of the other groups (P = .025). Schirmer values, tear film break-up time, and OSDI scores did not differ among groups (all P > .05). Within the CDKAI group, PE was not associated with treatment duration (P = .963) or tear film parameters. CONCLUSIONS AND RELEVANCE: In this comparative study, CDK4/6 inhibitor-based therapy was associated with significantly higher prevalence and severity of PE and vortex keratopathy, independent of aromatase inhibitor exposure and in the absence of measurable tear film dysfunction. These findings suggest a direct cytostatic effect on the corneal epithelium. Symptom scores were low, although OSDI interpretation was limited by incomplete responses. Proactive corneal surface evaluation with fluorescein staining may be warranted during CDK4/6 inhibitor treatment.

Humans↗
PubMed2026

LINC01871-Mediated Sensitivity to Cyclin-Dependent Kinase 4/6 Inhibitors in Human Breast Cancer.

Breast cancer remains the most frequently diagnosed malignancy in women, and resistance to cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors limits long-term treatment efficacy. This study aimed to identify long non-coding RNAs (lncRNAs) associated with predicted sensitivity to CDK4/6 inhibitors and to investigate their biological functions in breast cancer. Transcriptomic data from The Cancer Genome Atlas (TCGA) and drug sensitivity data from the Genomics of Drug Sensitivity in Cancer 2 (GDSC2) database were integrated, and drug sensitivity was predicted using the oncoPredict algorithm. Candidate lncRNAs were identified through differential expression analysis, weighted gene co-expression network analysis, prognostic analysis, and machine learning. The biological functions of LINC01871 were subsequently evaluated using in vitro and in vivo experiments. Sixty-two lncRNAs associated with predicted sensitivity to ribociclib and palbociclib were identified, and six core lncRNAs were selected. LINC01871 showed the highest discriminatory performance for predicted drug sensitivity. Overexpression of LINC01871 was associated with increased sensitivity of breast cancer cells to ribociclib and palbociclib, inhibition of cell proliferation, promotion of apoptosis, and suppression of nuclear factor kappa B (NF-&#x3ba;B) signaling. Single-cell transcriptomic analysis demonstrated high LINC01871 expression in T cells and natural killer (NK) cells, while transcriptome-based immune infiltration analyses showed that high LINC01871 expression was associated with increased immune infiltration. These findings identify LINC01871 as a candidate biomarker of sensitivity to CDK4/6 inhibitors and demonstrate its tumor-suppressive effects in breast cancer. Further clinical and mechanistic studies are required to validate its predictive value and therapeutic relevance.

Humans↗
PubMed2020

Combination of cyclin-dependent kinase and immune checkpoint inhibitors for the treatment of bladder cancer.

BACKGROUND: Perturbation of the CDK4/6 pathway is frequently observed in advanced bladder cancer. We investigated the potential of targeting this pathway alone or in combination with chemotherapy or immunotherapy as a therapeutic approach for the treatment of bladder cancer METHODS: The genetic alterations of the CDK4/6 pathway in bladder cancer were first analyzed with The Cancer Genome Atlas database and validated in our bladder cancer patient-derived tumor xenografts (PDXs). Bladder cancer cell lines and mice carrying PDXs with the CDK4/6 pathway perturbations were treated with a CDK4/6 inhibitor palbociclib to determine its anticancer activity and the underlying mechanisms. The combination index method was performed to assess palbociclib and gemcitabine drug-drug interactions. Syngeneic mouse bladder cancer model BBN963 was used to assess whether palbociclib could potentiate anti-PD1 immunotherapy. RESULTS: Of the 413 bladder cancer specimens, 79.2% harbored pertubations along the CDK4/6 pathway. Palbociclib induced G0/G1 cell cycle arrest but with minimal apoptosis in vitro. In mice carrying PDXs, palbociclib treatment reduced tumor growth and prolonged survival from 14 to 32&#xa0;days compared to vehicle only controls (p&#x2009;=&#x2009;0.0001). Palbociclib treatment was associated with a decrease in Rb phosphorylation in both cell lines and PDXs. Palbociclib and gemcitabine exhibited antagonistic cytotoxicity in vitro (CI&#x2009;>&#x2009;3) and in vivo, but palbociclib&#xa0;significantly enhanced the treatment efficacy of anti-PD1 immunotherapy and induced CD8+ T lymphocyte infiltration in syngeneic mouse models. CONCLUSIONS: The CDK4/6 pathway is feasible as a potential target for the treatment of bladder cancer, especially in combination with immunotherapy. A CDK4/6 inhibitor should not be combined with gemcitabine.

Animals↗
PubMed2026

Availability and public reimbursement of early breast cancer care across European expert centres: a PORTRAIT from an EUSOMA initiative.

BACKGROUND: Cross-country disparities in access to guideline-recommended early breast cancer care persist across Europe. PORTRAIT is a clinician-reported, cross-sectional access study mapping availability and state reimbursement of key services across the early breast cancer pathway. METHODS: A 49-item survey covering diagnostics, pathology and genomics, systemic therapy, surgery, radiotherapy, and supportive care was emailed from June to September 2024 to multidisciplinary teams at one expert breast centre in 42 European countries. Respondents provided a consensus perspective on service availability and reimbursement. Descriptive proportions with full, partial, or no access were calculated. RESULTS: Thirty-nine countries responded (93%). Core diagnostics were widely available, but gaps persisted: MRI-guided biopsy was absent in 29% of countries and vacuum-assisted biopsy was fully reimbursed in 66%. Genomic assays were unavailable in 14% and not fully reimbursed in 35%. Public funding gaps were reported for PARP inhibitors (33%) and CDK4/6 inhibitors (26%). Immediate implant-based reconstruction and biological meshes lacked reimbursement in 21% and 33%, respectively. Despite broad availability of hypofractionated radiotherapy, 38% of countries still used per-fraction reimbursement. Psycho-oncology was limited in 35%, fertility preservation in 46%, and patient-reported outcome measures absent in 43%. CONCLUSION: Basic services are nearly universal, but gaps persist in advanced imaging, molecular testing, targeted therapies, radiotherapy reimbursement, reconstructive/oncoplastic surgery, and survivorship care. PORTRAIT identifies practical targets for policy audit, reimbursement alignment, and resource stewardship. Findings reflect clinician perspectives from expert centres, potentially representing best specialist care rather than average national care, and are not population-representative estimates or direct measures of patient outcomes.

Humans↗
PubMed2026

Genomic profiling by circulating tumor DNA in patients with hormone receptor-positive/HER2-negative advanced breast cancer: Prevalence of actionable mutations across treatment lines.

INTRODUCTION: Plasma next-generation sequencing (NGS) is endorsed by ESMO as an alternative to tissue testing in advanced hormone receptor-positive, HER2-negative metastatic breast cancer (HR+/HER2- mBC), particularly after progression on endocrine therapy plus CDK4/6 inhibitors. However, prospective real-world data across distinct therapeutic contexts remain limited. PATIENTS AND METHODS: In this prospective observational study conducted within a nationwide cancer network in Brazil, centralized plasma NGS, and tissue NGS when available, was performed in two independent cohorts: prior to initiation of first-line endocrine therapy in the metastatic setting (Cohort 1) and at progression on endocrine therapy plus a CDK4/6 inhibitor (Cohort 2). The primary objective was to evaluate plasma-detected ESR1 mutation prevalence across these therapeutic contexts, and secondarily to assess other actionable drivers detected by plasma or tissue NGS. RESULTS: Among 86 collected plasma samples, 72 (84%) had evaluable NGS results (Cohort 1, n = 37; Cohort 2, n = 35). ESR1 mutations were identified in 18.9% of patients in Cohort 1 and 40.0% in Cohort 2, mostly at low variant allele fractions (<0.5%), corresponding to an absolute prevalence difference of 21.1 percentage points (95% CI, -0.2 to 40.3; P value=0.07). When considering any actionable alteration detected by plasma, including ESR1, PIK3CA, AKT1, PTEN, BRCA1, BRCA2, and ERBB2, prevalences were 43.2% and 68.6%, respectively (P value=0.04). Only four patients had ESR1 mutations identified in tissue, three in metastatic samples. Plasma-tissue concordance was higher for PIK3CA mutations (85.1%). CONCLUSION: Plasma NGS identified clinically meaningful ESR1 mutation rates across both contexts, supporting guideline-endorsed plasma-based genomic profiling in HR+/HER2- mBC.

CDK4/6 inhibitors↗
PubMed2026

PIK3CA in Cancer: Structure, Biology, Alterations, and Actionability.

PIK3CA, which encodes the p110&#x3b1; catalytic subunit of phosphoinositide 3-kinase (PI3K), is one of the most frequently altered oncogenes in human cancer and a major driver of tumor initiation, progression, metastasis, and therapeutic resistance. Over the past two decades, advances in structural biology, cancer genomics, and translational research have substantially expanded our understanding of PIK3CA function and established the PI3K pathway as a clinically actionable therapeutic target. This review provides an overview of the structural organization and physiological functions of the PI3K&#x3b1; complex, the molecular mechanisms underlying oncogenic activation, and the diverse spectrum of PIK3CA alterations across human malignancies. We also summarize the current landscape of PI3K-targeted therapies, highlighting both approved agents and emerging therapeutic strategies. Clinical evidence supports the rational integration of PI3K inhibitors with endocrine therapy, CDK4/6 inhibitors, MAPK pathway inhibitors, dual PI3K/mTOR inhibition, and immune checkpoint blockade. In addition, accumulating evidence indicates that PIK3CA plays a pivotal role in shaping the tumor immune microenvironment, providing a biological rationale for combining PI3K inhibition with immunotherapy. Finally, we discuss future directions in precision oncology, emphasizing integrated molecular profiling, liquid biopsy, single-cell and spatial technologies, functional genomics, and evolutionary approaches as complementary strategies to refine patient selection, overcome therapeutic resistance, and optimize clinical outcomes.

PI3K signaling↗
PubMed2026

Rb-driven transcription limits its tumour-suppressive effects in breast cancer.

The retinoblastoma protein (Rb) is a tumour suppressor best known for repressing E2F transcription factors and halting cell cycle progression1. In hormone receptor-positive (HR+) breast cancer, CDK4/6 inhibitors activate Rb by preventing its phosphorylation, forming a key component of current endocrine therapy regimens2. How pharmacologically activated Rb remodels chromatin and influences transcription beyond cell cycle arrest remains poorly understood. Here we show that CDK4/6 inhibition induces redistribution of hypophosphorylated Rb to promoters and enhancers. Although Rb predictably binds to cell cycle gene promoters to repress transcription, at other sites, it unexpectedly promotes expression of oestrogen-responsive genes by integrating into oestrogen receptor (ER)-rich transcriptional hubs. CDK4/6 inhibition enhances ER target gene expression in breast cancer cells, patient-derived xenografts and clinical HR+ breast cancer samples in an Rb-dependent manner. This reprogramming is mediated in part by KDM5A, whose interaction with Rb contributes to gene regulation at these loci. Critically, components of this Rb-driven ER transcriptional program are pro-proliferative. In endocrine-sensitive tumours, this effect&#xa0;can be neutralized with anti-oestrogen therapy, explaining therapeutic synergy. In endocrine-resistant settings such as ESR1-mutant breast cancer, the program persists, limiting the&#xa0;therapeutic efficacy&#xa0;of&#xa0;CDK4/6 inhibition. These findings reframe Rb as a dual-function transcriptional regulator that, although enforcing cell cycle arrest, can also activate programs that counteract its tumour suppressor function.

Humans↗
PubMed2025

Neoadjuvant palbociclib in women with operable, hormone receptor-positive breast cancer.

The addition of a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor to endocrine therapy augments biological response in breast cancer. This phase III randomized, double-blind study evaluated the efficacy of adding palbociclib to neoadjuvant endocrine therapy (NET) for operable, hormone receptor-positive human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Patients randomly received 16 weeks of endocrine therapy (letrozole for postmenopausal and tamoxifen plus ovarian function suppression for pre-/perimenopausal patients) plus palbociclib or placebo. The co-primary endpoints included preoperative endocrine prognostic index (PEPI) score and EndoPredict (EPclin) risk score according to the gatekeeping procedure. Of 141 randomized patients, 130 completed the treatment with surgical samples evaluable for endpoints in 126 patients. The proportion of patients with a low, moderate, and high PEPI score was 15.2, 50.0, and 34.8% in the palbociclib arm and 13.3, 55.0, and 31.7% in the placebo arm, respectively, with no statistical difference (one-sided P = 0.563). Statistical analysis was not performed on EPclin risk score. No new safety signals were reported. Permanent treatment discontinuation by adverse events was reported for seven (9.7%) and zero patients in the palbociclib and placebo arms, respectively. In conclusion, the addition of palbociclib to NET did not improve the efficacy. ClinicalTrials.gov NCT03969121.

Humans↗
PubMed2026

Navigating uncertainties and evidence gaps in adjuvant therapy for premenopausal women with HR+/HER2- breast cancer.

Premenopausal women with hormone receptor-positive (HR+)/HER2-negative early breast cancer represent a clinically distinct population, characterized by more aggressive tumor biology, unique survivorship concerns, and complex treatment decision-making. Although evidence from dedicated trials and subgroup analyses is available, management remains challenging because data are heterogeneous, evolving, and often extrapolated from broader populations that include predominantly postmenopausal women. Adjuvant endocrine therapy, with the addition of CDK4/6 inhibitors in selected higher-risk patients, remains the cornerstone of treatment; however major uncertainties persist regarding the optimal use of ovarian function suppression, the interpretation of genomic assays to inform chemotherapy decisions, the selection of candidates for extended endocrine therapy, and the management of adherence, treatment-related toxicities, pregnancy-related issues, and survivorship concerns. Here, we synthesize current evidence across these domains and propose a pragmatic clinical framework to support individualized treatment strategies and optimize care for this population in the contemporary therapeutic landscape.

HR+/HER2- early breast cancer↗
PubMed2026

Inhibiting cyclin D1-CDK6 suppresses senescence-associated inflammatory gene expression and age-related functional decline.

Cellular senescence contributes to aging and age-related diseases by driving chronic inflammation through the senescence-associated secretory phenotype (SASP), including interferon-stimulated genes (ISGs). Here we confirm and extend previous observations that cyclin D1 (CCND1), a key cell cycle regulator, is paradoxically upregulated across models of nonproliferating senescent cells. We show that CCND1 and its kinase partner CDK6 drive SASP and ISG expression in senescent cells by promoting DNA damage accumulation. This leads to the formation of cytoplasmic chromatin fragments that activate pro-inflammatory cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling. In aged mouse livers, senescent hepatocytes show increased Ccnd1 expression. Hepatocyte-specific Ccnd1 knockout or treatment with the clinical grade CDK4/6 inhibitor palbociclib reduces DNA damage and ISGs in aged mouse liver. Further, palbociclib suppresses frailty and improves physical performance of aged mice. These findings demonstrate a role for CCND1/CDK6 in regulating DNA damage and inflammation in senescence and aging, highlighting it as a promising target for therapeutic repurposing.

Animals↗
PubMed2025

Next-generation sequencing in breast cancer: current clinical applications and future directions.

INTRODUCTION: Breast cancer is a heterogeneous disease that claims 670,000 lives by 2022. Omic technologies, particularly next generation sequencing (NGS) offers promising avenues for precision medicine. American Society of Clinical Oncology (ASCO) outlines genomic testing's utility, emphasizing prognostic and diagnostic potential. OBJECTIVES: This review succinctly explores NGS's evolution and clinical applications of NGS in breast cancer, thereby guiding future research to enhance patient care. METHODS: Comprehensive literature searches were conducted using databases such as PubMed, Google Scholar, and ResearchGate, focusing on keywords including breast cancer, HER-2 low breast cancer, circulating tumour DNA, single-cell RNA sequencing, and next-generation sequencing. Peer-reviewed, high-quality articles published in English were selected for inclusion. RESULTS: Previous studies have explored the evolution of NGS technology and its clinical applications in breast cancer, including genomic and transcriptomic characterization, treatment guidance, and resistance prediction. Molecular profiling of challenging entities such as early-onset breast cancer and HER-2 low tumours was summarized, with key findings highlighted. This review also discusses emerging technologies, including circulating DNA and single-cell sequencing, as promising avenues for discovery. CONCLUSION: NGS has revealed the genomic and transcriptomic diversity of breast cancer, identifying actionable alterations associated with chemotherapy response and resistance to therapies such as trastuzumab, TKIs, and CDK4/6 inhibitors. Circulating tumour DNA (ctDNA) shows potential for diagnosis, prediction, prognosis, and monitoring, despite tumour heterogeneity. Single-cell analysis enables exploration of individual cell transcriptomes, though high costs and low throughput remain barriers to widespread adoption. HER2-low tumours continue to pose significant research challenges.

Humans↗
PubMed2025

Targeting CyclinD1-CDK6 to Mitigate Senescence-Driven Inflammation and Age-Associated Functional Decline.

Cellular senescence contributes to aging and age-related diseases by driving chronic inflammation through the Senescence Associated Secretory Phenotype (SASP) and interferon-stimulated genes (ISGs). Cyclin D1 (CCND1), a key cell cycle regulator, is paradoxically upregulated in these non-proliferating cells. We show that CCND1 and its kinase partner CDK6 drive SASP and ISG expression in senescent cells by promoting DNA damage accumulation. This leads to the formation of cytoplasmic chromatin fragments (CCFs) that activate pro-inflammatory CGAS-STING signaling. The tumor suppressor p53 (TP53) and its target p21 (CDKN2A) antagonize this CCND1-CDK6-dependent DNA damage accumulation pathway to suppress the SASP. In aged mouse livers, senescent hepatocytes show increased Ccnd1 expression. Hepatocyte-specific Ccnd1 knockout or treatment with the Cdk4/6 inhibitor Palbociclib reduces DNA damage and ISGs in aged mouse liver. Notably, Palbociclib also suppresses frailty and improves physical performance of aged mice. These findings reveal a novel role for CCND1/CDK6 in regulating DNA damage and inflammation in senescence and aging, highlighting it as a promising therapeutic target.

Journal Article↗
PubMed2026

Spatial habitat radiomics predicts tertiary lymphoid structure status and identifies an IDO1+ migratory dendritic cell axis in breast cancer.

BACKGROUND: Tertiary lymphoid structures (TLS) are spatially organized immune niches associated with therapeutic response and favorable outcomes in breast cancer (BC). However, TLS assessment currently relies on invasive tissue-based analyses, and the biological mechanisms underlying imaging-based TLS prediction remain poorly understood. METHODS: We developed and validated a spatial heterogeneity-based radiomic TLS signature (shTLS) using dynamic contrast-enhanced MRI to non-invasively predict TLS status across multicenter BC cohorts. Spatial habitat radiomics were used to capture intratumoral and peritumoral immune-related heterogeneity. Integrated multi-omics analyses, including transcriptomics, pathomics, genomics, single-cell RNA sequencing, immunohistochemistry, and multiplex immunofluorescence, were performed to biologically interpret shTLS-defined subgroups. Functional drug-sensitivity assays were conducted to assess therapeutic implications. RESULTS: The shTLS model achieved robust predictive performance across independent cohorts and molecular subtypes. High shTLS scores were associated with immune-inflamed tumors characterized by spatially clustered activated T cells and dendritic cells (DCs). In contrast, shTLS-low tumors exhibited an immunosuppressive spatial niche with peripheral accumulation of CD4+ PD-1+ T cells and plasma cells, increased immune-tumor separation, and enhanced inflammatory and immunoregulatory signaling. An indoleamine 2,3-dioxygenase 1 (IDO1)-associated immunoregulatory program was observed in the shTLS-low tumors, which appeared to be preferentially expressed by LAMP3+CCR7+ migratory DCs. Pharmacologic inhibition of IDO1 enhanced chemotherapy and CDK4/6 inhibitor sensitivity in vitro. CONCLUSION: This study establishes spatial radiomics as a non-invasive approach to decode TLS-associated immune ecosystems and supports the presence of an IDO1-associated immunosuppressive phenotype, providing biological insight and translational rationale for patient stratification and future combination strategies.

Humans↗